THE APPARENTLY ISOLATED CHOROID-PLEXUS CYST - IMPORTANCE OF MINOR ABNORMALITIES IN PREDICTING THE RISK FOR ANEUPLOIDY

Objectives: To assess the risk of aneuploidy in cases of isolated chor oid plexus cysts (CPCs) and to compare the risk when associated with m inor or major anomalies. Methods: Ail fetuses with CPCs and known kary otype were identified. CPCs were categorized as 'isolated' or associat ed with minor or major sonographic anomalies. Preexisting risk factors for aneuploidy were compared between groups. The frequency of aneuplo idy was compared between fetuses with isolated CPCs and those with CPC s associated with minor or major anomalies. Continuous and categorical variables were analyzed using one-way analysis of variance or chi-squ are as appropriate with p < 0.05 considered significant. Results: One hundred and forty-nine fetuses with CPCs diagnosed at a mean gestation al age of 19 weeks were identified. No significant differences in the frequency of preexisting risk factors for aneuploidy were identified b etween groups. Eighteen of 149, (12%) fetuses with CPCs had other sono graphic anomalies; in 10 they were minor, and 2 of the 10 had abnormal karyotypes. Four of 8 fetuses with major anomalies were aneuploid. Al l 131 fetuses with isolated CPCs had normal karyotypes, and all aneupl oid fetuses had additional anomalies. Conclusions: The overall rate of aneuploidy in patients with CPCs was 4% with no abnormal karyotypes a mong isolated CPCs. The presence of even minor sonographic abnormaliti es substantially increased the risk of aneuploidy. Isolated CPCs ident ified sonographically may not place the patient at risk of aneuploidy, but should prompt a diligent search for other minor or major anomalie s. The finding of any other anomaly warrants consideration for karyoty pic evaluation.